Pneumatic drilling-machine



'1. w.1IERIIEY AND I'. IIILLs.

PNEUMATIC'DRILLING MACHINE.

APPLICATION FILED SEPLU, I92o.

UNITED .STATES PATENT OFFICE..

JOHN WILBUR TIERNEY, OF ASHTREE, AND FRANK HILLS, vOF UPTON, LONDON,

, ENGLAND.

PNEUMATIC DRILLING-MA'CHINE 'Application led September 27, 1920.

To LZZ whom t may concern.:

Be it known that we, .loi-IN lViLiiuiz Tinu- NEY, a citizen ot` theUnited States of America, residing at Ashtree, Beulah Hill, Norwood, inthe county of Surrey, England, and FRANK HILLS, a subject of the King otGreat Britain, residing` at 210 Neville road, Upton, London, England,have invented cer tain new and useful Improvementsin or llelating toPneumatic Drilling-Machines, of which the following Vis a specification.

Thepresent invention relates to pneumatic drilling machines and moreparticularly to the means used for exhausting air therefrom and isespecially applicable to pneumatic drilling machines of the portabletype.

Accordingto this invention, a device is provided whereby the escape otthe live air which leaks past the pistons and valves into the freechambers ot such a machine is et'- fected throughand controlled by thethrottle handle so as to insure a :tree exhaust of the said live airwhen the said machine is in operation and so as to close the saidexhaust and prevent any escape ot' lubricant therefrom when the saidmachine is not in use. The aforesaid device may consist ot' a number ofsuitably arranged holes or vents and passages which are adapted to putthe' crank chamber and other free air chambers ot' the machine incommunication with the throttle handle thereof and which are arranged sothatl communication to atmosphere ot' these free air chambers iscontrolled by means of the throttle sleeve.

rThe above-mentioned holes or vents which may be conveniently drilledinthe casing of the machine, may advantageously be drilled to thelevelof the upper part ot' the valves and made to -communicate with a smallerhole or vent provided in `the upper part of the valve chambers in orderto prevent any leaking' and accumulating air from exerting an end thruston the said valves. The intercommunicating passages provided in thethrottle handle may be arranged so as to operate in conjunction with asuitable slot or the like adapted to be controlled by a suitably shapedand dimensioned groove in the throttle sleeve so that when the throttleis in the open position the aforesaid vent holes and passages are opento a tree exhaust, and when the said throttle sleeve is turned in theappropriate direction the said Specification of Letters Patent.

Patented Oct. 18, 192.1.

serialr No. 413,164.

vent holes and passages as well as the ail` inlet are closed.

In order that the said invention may be clearly understood and readilycarried into effect, the same will now be described `more fully with'reference to the accompanying drawings in which- 'Figure l is avertical section taken through a pneumatic drilling machine constructedin accordance with our invention.

Fig. 2 is a horizontal section showing the cylinders and the arrangementof the passages in the throttle.

Fig. 3 is avsection drawn taken along the line 2 2 of Figs. d and 5 arerespectively vertical sections drawn to a. larger scale taken along thelines 4-4 and 5-5 of Fig. l.

A is the casing ot the machine B-B are the holes or vents drilled in thecasing A and communicating with the crank chamber a and other free airchambers of the machine. Tlie said holes or vents B, -B also communicatewith the smaller holes or vents C, C provided in the upper part of thevalve chambers D, D (see Fig. 3) in order to prevent any leakingl andaccumulating air from exerting an end thrust on the valves CZ d. Thesaid holes or vents B, B communicate with the throttle handle E throughthe passages Z) Z) (see Figs. l, 2 and 4l) which lead to the passages bxbx that communicate through the transverse passage e. The said throttlehandle E is formed with the three passages c', c2, e3 for the admissionand exhaust ot the operating iuid which is controlled by the sleeve Fwhich constitutes the throttle proper and is adapted to be ro tated uponthe throttle handle E. The said sleeve F is provided withthe twopassages to a larger scale Fig. 2, and

', which whenthesleeve is in the position shown in the drawing permitsthe operating Huid to enter the cylinders of the machine through thepassages e', f 'and e2 and exhaust therefrom through the passages c3 andf. It the said sleeve be turned through 90o in the direction ol thearrow (see Figs. 4 and 5) the said passages e2 and e3 are closed by thesaid sleeve and the machine becomes inoperative, if the sleeve beAfurther rotated in the saine direction through a further 900 themachine becomes operative again but works in the opposite direction asthe passages e e3 become inlet passages and the slot f2 (see Figs. 2 and4) so that when vthe machine is operating that is to say when the sleeveF is turned to admit the operating Huid as shown in the drawing, thesaid holes or vents B Bare open to the atmosphere and when the sleeve Fis turned to cut ott' theluid the said intercomsupply of operatingclosed by the walls municating passage e is v of the sleeve F, therebypreventing any lealzing of lubricating oil from the machine when' thelatter is lying idle. The said holes or vents operate as aforesaidwhether the machine is running in a clock-wise or anticlockwisedirection according` to the posi-.

tion of the said sleeve F. In some cases the exhaust Jroin the saidholes or vents may be independent of the main exhaust of the machine.

A device in accordance with the present invention insures that theleaking live air is effectively exhausted and guards against the dangerof any back pressure taking place owing to an undue accumulation of air1n the casing ot' the machine. The said device further insures that nolubricating `oil is blown to atmosphere, or leaks away when the machineis not in use, as is the case with certain exhausting devices which havebeen hitherto employed. Furtheror-e when the machine is used forsubmarine work excessive bubbling is avoided as the leaking live airinstead of esca-ping through the jointsl of the casing of the machineand causing inconvenience to the diver passes up the exhaust pipe withwhich such machines are provided.

What we claim and desire to secure byV Letters Patent ot the UnitedStates is l. In a pneumatic drilling machine, the combination of athrottle handl having passages communicating with the free air spaces ofthe machine, means :tor placing such passages in communication with theatmosphere, and means for closing such passages.

2. In a pneumatic drilling machine, the combination of a throttlehandle, having passages communicating with the free air spaces and valvechambers of the machine, means for placing such passages incommunication with the atmosphere, and means 'for closing such passages.i

3. In a pneumatic drilling machine, the combination of a throttlehandle, having passages communcatingwith the free air spaces of themachine, means for simultaneously opening the main inlet of the machineand placing said passages in Vcommunication with the atmosphere, andmeans for simultaneously closing` said inlet aiid'closing said passages.v j j 4C. ln a pneumatic drilling machine,the combination of a throttlehandle,having passages communicating with the free air spaces 'and valvechambers of the niacliine,vmeans for simultaneously opening.;- the maininletof the machine and placing said passages in communication with theatmosphere, and means for simultaneously closing said inlet and closingsaid passages.

'5. In a pneumatic drilling machine, the combination oi a throttlehandle having a slot therein and communications therethrough betweensaid slot and the free air spaces of the machine, a throttle sleeverotatable in relation to said throttle handle to open and close the maininlet of the machine, the said sleeve comprising an outlet to theatmosphere and a groove communicat-` ing with said outlet, said groovebeing in register with said slot when said sleeve opens said inlet andbeing withdrawn from said slot when said sleeve closes said inlet.` 6.ln a pneumatic drilling machine, the

combination of a throttle handle having a slot therein andcommunications therethrough between said slot and the free air spacesand valve chambers of the machine, a throttle sleeve rotatable inrelation to said throttle handle to open' and closeV the main inlet ofthe machine, the said sleeve comprisingA an outlet 'to the atmosphereand a groove cominunicating1 with said outlet, said groove being inregister with said Slot when said sleeve opens said inlet and beingwithdrawn from said slot when said sleeve closes said inlet. Y

. Joint wiLBun Tinnunv,

FRANK niLLs.

